A wide range of devices use displays to convey information to a user. Displays are becoming increasingly common on various devices, including both mobile devices and stationary devices. For example, various electronic devices, such as mobile phones, personal digital assistants (“PDAs”), smartphones, laptops, netbooks, tablet computers, desktop computers, and various other handheld devices use displays to convey information and/or provide entertainment to a user. Devices such as automated teller machines, vending machines, and parking meters, are frequently using displays to convey information to a user. Additionally, vehicles such as cars, trucks, busses, trains, airplanes, and boats frequently have displays for providing information to passengers. Essentially, displays are becoming an increasingly common component of devices in all facets of life.
For example, the trend of using displays is particularly prominent with portable electronic devices such as cellular phones. There is somewhat of a trend towards using touch screen displays in many portable electronic devices, and generally, there is a trend to make displays larger. However, the trend to increase display size is typically at odds with a trend to decrease the size of portable electronic devices. A common theme with portable electronic devices is that users typically prefer devices that are compact and have a long battery life, which promotes simplified transporting of the device and ease of use in remote locations without requiring any connection to a power grid.
While users often prefer smaller devices with relatively large display screens, there are some drawbacks to electronic devices of the prior art. The trend to make electronic devices with larger display screens and/or touch screens has caused the display in many devices to consume a relatively large amount of power. Accordingly, devices have included light sensors to determine whether the ambient light level requires the display to operate at a maximum brightness level. For example, a display may operate at a maximum brightness level if the device is located outside in the sunlight, so that the user of the device can adequately see the image displayed. However, the display may operate a limited brightness level if the device is located in darkness, because the image does not need to be displayed with the maximum brightness for the user to see the image. By altering the brightness level of the display, the device can conserve power when the ambient light level of the device low, while still providing an image the user can see when the ambient light level is high.
The prior art methods of dealing with setting the display brightness includes using ambient light sensors. Light sensors are often difficult to implement in an optimal position on a device because of device design limitations. For example, on a mobile phone, light sensors may be located in the corner of a device, which can decrease the effectiveness in detecting the ambient light if that corner is covered by a user's hand or otherwise obstructing the actual ambient light level from being sensed. For example, if a mobile phone included ambient light sensors prominently located in various positions of the phone to ensure proper ambient light detection, the device may be unappealing to users because of the non-discreet location of the light sensors. Accordingly, there is a trend in minimizing the noticeability of the ambient light sensors on mobile devices by placing the light sensors in a discreet location and making the light sensors small in size. By putting the light sensor in a more discreet location, a device may be seen as having an improved look, however, the actual effectiveness of the light sensor may be decreased based on its position. If ambient light is not properly detected, the device may use more power than necessary to adequately display an image. Accordingly, failing to optimally control the brightness of an image and the power to display the image lowers efficiency and can decrease battery life. Further, an ambient light sensor may use power from a device battery or other power source, which decreases the battery life and/or makes the device less efficient. Typically, users prefer long battery life and/or high efficiency products, so decreasing power consumption is generally desirable to users.
Accordingly, manufacturers and users of devices face challenges detecting ambient light, controlling power used by a display based on the ambient light, and in prolonging battery life and/or increasing device efficiency. The prior art fails to provide a sufficient solution for the above described challenges.